1. Field of the Invention
This invention relates to pea harvesters.
2. Description of the Prior Art
Currently various machines are available for harvesting peas but the ever-increasing requirement for "garden" peas makes it necessary further to develop and improve such harvesting machines in order to increase the efficiency of collection and/or to enlarge the capacity of a given size of harvester. The need for efficiency in collection has become more important and will continue to do so with increasing food shortages on a world-wide scale and furthermore efficiency in collection can avoid difficulties for the grower in the following season since an excessive loss of peas in the field at harvesting can be embarrassing if a different crop is grown in the following year.
Some currently employed pea harvesting systems involve first the cutting by one machine of the rows of pea vines with the subsequent passage over the same ground of a mobile viner which threshes and cleans the pea vines which are picked up, returns the chaff, leaves and empty pods directly to the field and accumulates a store of "clean" peas for eventual transfer to a carrying vehicle.
In certain instances where the fields are a long way from the freezing plant or cannery an alternative form of viner could pick up the plants directly without previous cutting and immediately return the empty vines to the field while cleaning the pods and returning the leaves and other like matter to the field, storing undamaged pods and from time-to-time transferring them to a transport vehicle. The undamaged pods are then conveyed to the freezing plant or cannery where they are threshed and the empty pods disposed for composting while the peas are treated at the cannery for marketing.
While the possible mode of operation discussed in the immediately preceding paragraph has advantages in certain circumstances, ideally the peas are efficiently cleaned and made substantially ready at the time they leave the field for processing either by freezing or canning. Pea harvesting machines should therefore serve to pick, thresh and thoroughly clean the peas, return the empty vines to the field prior to the threshing and cleaning process and finally the chaff, leaves and empty pods should be returned to the field during the threshing and cleaning process. The peas are preferably stored and from time-to-time are transferred to a transport vehicle. Furthermore, losses should be kept to a minimum even when the harvester is working uneven ground.
Although proposals have been made for mounting pea harvesters on conventional tractors, in some circumstances, a purpose-built complete machine presents advantages since generally peas are grown as a specialist crop and the growers will be more concerned to have a readily available machine in such specialist circumstances than would be desirable where general farming is carried out.
It is accordingly one object of the present invention to provide a pea harvester incorporating a threshing means which must be maintained at a constant orientation "in space" and a conveyor system which accommodates local irregularities in the ground while continuing to feed crop to the thresher with small losses.
A further object of the present invention is to provide a hopper assembly which can receive crop continuously thereby enabling an associated harvester to operate continuously.
A still further object of the present invention is to provide a harvester in which the fore-and-aft balance of the harvester is improved.
A yet further object of the present invention is the provision in a pea harvester with a forward pick-up means and a hydraulic circuit for supporting a proportion of the weight of the pick-up means.